Opera's most popular double bill, fondly known as Cav and Pag, can be a tawdry mess or, as in this performance of Pagliacci, a searing experience. Its power derives from an all-star cast headed by tenor Jon Vickers in the double role of betrayed husband, Canio, and tragic clown, Pagliacci. He’s a singer who blurred the division between reality and stage illusion in every role he assumed, thus taking an opera about that thin line between real life and stage artifice to heightened levels of intensity. Vickers is a force of nature, his big, brawny voice suffused with emotion. Here, his phrasing, textual precision, and timbral colorations expand the scope of the opera, making a moving tragedy out of Leoncavallo’s verismo melodrama.